giải mình câu này với

`\sqrt{5-2\sqrt{6}}+\sqrt{5+2\sqrt{6}}`

`=\sqrt{(\sqrt{3})^2-2\sqrt{2}.\sqrt{3}+(\sqrt{2})^2}+\sqrt{(\sqrt{3})^2+2\sqrt{2}.\sqrt{3}+(\sqrt{2})^2}`

`=\sqrt{(\sqrt{3}-\sqrt[2})^2}+\sqrt{(\sqrt{3}+\sqrt{2})^2}`

`=|\sqrt{3}-\sqrt{2}|+|\sqrt{3}+\sqrt{2}|`

`=\sqrt{3}-\sqrt{2}+\sqrt{3}+\sqrt{2}`

`=(\sqrt{3}+\sqrt{3})+(-\sqrt{2}+\sqrt{2})`

`=2\sqrt[3}+0`

`=2\sqrt{3}`